The present invention relates to a lead frame for a semiconductor device, a semiconductor device using the lead frame, and a method for manufacturing the semiconductor device.
FIG. 18 is a perspective view of a conventional lead frame. In FIG. 18, numeral 31 denotes a frame, numeral 32 a half-etched inner lead formed continuously with the frame 31, numeral 33 an external terminal leading portion of the inner lead 32, numeral 34 a die pad, numeral 35 a chip placed on the die pad 34, and numeral 36 a support tape for supporting the inner lead 32.
FIG. 19 is a semiconductor device which is formed with the use of the conventional lead frame. In FIG. 19, numeral 37 denotes a die bond material for bonding a chip 35 on a die pad 34, numeral 38 a bonding wire for connecting an inner lead 32 with a bonding pad of the chip 35, numeral 39 a sealing resin for sealing the inner lead 32 and the chip 35, and numeral 40 a soldering ball on an external terminal leading portion 33.
The conventional lead frame shown in FIG. 18 and FIG. 19 has many inner leads 32. Each inner lead is so narrow that it is weak in mechanical strength. To reinforce the tip end or the intermediate position of the lead to be wire-bonded and to avoid defects, such as bending, it is necessary to adhere a support tape 36 to portions requiring reinforcement as shown in FIGS. 18 and 19. With respect to the die pad 34, it is necessary to provide an inner lead for support or to provide reinforcement by adhering a support tape as in the described inner lead.
For example, in Japanese Unexamined Patent Publication No. Hei. 3-94459, there is introduced a technology of forming a terminal by etching, after a chip is mounted, with the use of a metal base on which no lead is formed. The technology is not, however, suitable for formation of the lead frame.
A primary object of the present invention is to solve such a problem, and to provide a lead frame capable of avoiding defects such as bending in the lead frame body without using the support tape.
A second object of the invention is to provide a lead frame capable of fine processing and use even in a semiconductor device having a Chip Scale Package (CSP) structure.
A third object of the invention is to provide a method for manufacturing such a lead frame.
Further, a fourth object of the invention is to provide a semiconductor device having a CSP structure or the like using such a lead frame.
A fifth object of the invention is to provide a method for manufacturing such a semiconductor device.